Stretching before exercise may inhibit performance?

The Introduction

group stretchingAll of us appreciate the importance of stretching before training or racing. The reason? It’s supposed to increase the range of motion about the joint and also prevent injuries isn’t it? Recent research has shown that static stretching just before strength or power events may inhibit performance for up to 60 minutes after stretching. This American study showed that a 30-second static stretch  decreases strength performance.

The Research

Eighteen college-aged students (10 males, 8 females) performed a one repetition maximum (1-RM ) test of knee-flexion (hamstring curl) following 0, 1, 2, 3, 4, 5, or 6 x 30-s bouts of static (holding) hamstring stretching. All seven dose variations were done by each subject, with each variation done on a separate day. One week separated each test, and the order of the stretch variations was balanced across the seven testing days. The stretching program used a passive, static, sit-and-reach hamstring stretching exercise. To do this stretch, the participants sat on the floor with the legs extended and then lowered their head toward the knees. Once the participant was in position, one of the experimenters would push the person’s back until the participant verbally acknowledged that the hamstring muscles were experiencing the maximum amount of tolerable tension. The experimenter would then hold the participant’s body at that position for the 30 s. On the days of multiple stretches, a 15-s recovery period intervened between the repetitions. Following the stretching bout, the participant would relax for 10 min before doing the 1-RM test.

The Results

The main finding was a significant reduction in knee flexion strength following as little as one 30-s stretch of the hamstrings. Another finding was that further stretching increasingly inhibited strength performance the more 30-second stretches were done. One 30-second stretch decreased hamstring 1 RM strength by 6.3% with 6 consecutive 30-second stretches decreasing strength by 12.1%.

The So What?

These results support another recent study that examined the effect of static stretching on isometric (tensing muscles without movement) strength in healthy and active women aged 64.6±7.1 years (Gurjao and others, 2009) who showed decreased isometric strength after static stretching. Taken together, these studies strongly suggest that athletes and coaches wishing to maximize strength and power performance should avoid any static stretching just prior to sporting activity where strength and power are important. This suggests that static stretching should be done well before the event(s) and ballistic and sports-specific warm-ups should be done closer to the event.

 Winchester, J., Nelson, A., Kokkonen, J. (2009). A single 30-s stretch is sufficient to inhibit maximal voluntary strength. Research Quarterly for Exercise and Sport. 80(2): 257 – 261.

 Gurjao, A., Goncalves, R., de Moura, R., Gobbi, S. (2009). Acute effects of static stretching on rate of force development and maximal voluntary contraction in older women. Journal of Strength and Conditioning Research. 23(7): 2149-2154.

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